Digital Radio Detectors for Galactic PeV Particles

Objective

The most energetic particles in our Galaxy are accelerated by yet unknown sources to energies much beyond the reach of human-made accelerators such as LHC at CERN. The detection of PeV photons from such a natural Galactic accelerator will be a fundamental breakthrough. For this purpose I propose a digital radio array for air showers at South Pole building on my proven expertise in successfully setting up and managing an antenna array in Siberia. Recently, we have discovered that by using higher radio frequencies than before the energy threshold can be lowered dramatically from 100 PeV to about 1 PeV. The new radio array will significantly enhance the present PeV particle detectors at South Pole in both, accuracy and aperture towards lower elevations. One of the most promising candidates for the origin of cosmic rays, the Galactic Center presently outside of the field of view, will be observable 24/7 with the radio array. The extrapolation of classical TeV observations predicts more than twenty PeV photons to be detected by the radio array within three years. Since the radio array is sensitive simultaneously to cosmic photons and charged particles from all directions of the sky, the search for any photon sources can be done in parallel to cosmic-ray physics with unprecedented accuracy and exposure in the energy range of 1 PeV to 1 EeV. Thus, this radio array will create highest impact in astroparticle physics by the following scientific objectives all targeting the most energetic particles in our Galaxy: PeV photons and their correlation with sources of neutrinos and charged cosmic rays, mass separation of cosmic rays, search for mass-dependent anisotropies, particle physics beyond the reach of LHC. This timely proposal is a unique chance for European leadership in this novel technique. It provides the chance for scientific breakthrough by detection of the first PeV photons ever, and by the discovery of natural accelerators of multi-PeV particles.